Pneumatic feed system for cigarettemaking machines



June 4, 1968 PNEUMATIC FEED SYSTEM FOR CIGARETTE-MAKING MACHINES Filed May 3, 1966 BALLARD, JR 3,386,773

4 Sheets-Shea: 1

INVENTOR. nu/vc/s .7. 5,011,020, .74,

MQMMW June 4, 1968 F. J. BALLARD. JR 3,336,773

PNEUMATIC FEED SYSTEM FOR CIGARETTE-MAKING MACHINES Filed May 5.- 1966 4 Sheets-Sheet 2 June 4, 1968 F. BALLARD, JR

PNEUMATIC FEED SYSTEM FOR CIGARETTE-MAKING MACHINES 4 Sheets-Sheet 5 Filed May 5, 1966 INVENTOR.

Flaw/v05 a M41420, J2.

ATTO/P/VEXS June 4, 1968 F. .J BALLARD, JR 3 9 PNEUMATIC FEED SYSTEM FOR CIGARETTEMAKING MACHINES Filed May 5, 1966 4 Sheets-Sheet 4 dis?! INVEN'TQR Fem as .7. 5191mm; .72..

a: ATTORNEYS United States Patent 3,386,773 PNEUMATIC FEED SYSTEM FOR CIGARETTE- MAKING MACHINES Francis J. Ballard, Jr., Louisville, Ky., assignor to Brown & Williamson Tobacco Corporation, Louisville, Ky., a corporation of Delaware Filed May 3, 1966, Ser. No. 547,333 17 Claims. (Cl. 302-28) ABSTRACT OF THE DISCLOSURE A pneumatic conveying system for out tobacco is pro vided in which a tobacco feeder is adapted to supply tobacco for cigarette-making machines. A number of other feeders may be similarly employed for the making machines for the same or other brands. The operation of each feeder is controlled and will start to feed cut tobacco to a demanding making machine upon the attainment of a predetermined conveying velocity within the pneumatic system. A main feed pipe leads from the feeder with branch lines extending therefrom to the making machines to be supplied with cut tobacco by the feeder. A main suction line extends from the suction-producing equipment with branch lines similarly extending to the cigarettemaking machines. The pneumatic system is designed to feed only one of the making machines at a time upon request for cut tobacco. A tobacco separator is associated with each of the making machines. A screen within the separator serves to separate the cut tobacco from the conveying air stream. As the cut tobacco fills the separator, the pressure drop across the separator progressively increases. When this pressure drop reaches a preset level, the suction side of the separator closes and a trap door of the separator will now swing open and the collective tobacco is permitted to fall int-o the selected making machine hopper.

The present invention relates to a system for automatically feeding and conveying tobacco from one area to another and, more particularly, to a system for automatically feeding and conveying rag or cut tobacco from a storage area to a cigarette-making machine.

In the past, a number of pneumatic feed systems for cigarette-making machines have been proposed but practically all have experienced operational difficulties primarily because of the physical layout of the tobacco handling and storage and the cigarette-making operations. Ordinarily, rag or cut tobacco will be stored at a location many hundreds of feet away from the cigarette-making machines and in a majority of instances, at a level or floor of the manufacturing plant different from that on which the making machines are located. Consequently, many cigarette manufacturing plants still load each making machine hopper with a skip-conveying system utilizing overhead chain conveyors or the like for-moving manually loaded skips or bins of rag tobacco from a storage area to the making machine at which the skips are unloaded by a trip mechanism. The disadvantages and obsolescence of this type of equipment and maintenance requirements are too well known in the art to justify analysis and. discussion at this time.

With this briefly described background information, it is a principal object of this invention to provide an improved pneumatic feed system for cigarette-making machines where-by r-ag tobacco is pneumatically conveyed for distances upwards of nine hundred feet from one floor or building to another where primary leaf processing and rag storage are located as well as pneumatically conveying rag tobacco to a multi-floor cigarette-making machine building and over substantially straight vertical rises of upwards of sixty feet and through bends and turns that may total upwards of and more.

Another object is to provide a pneumatic system capable of individually feeding as much as ten cigarette-making machines and more whose total rag tobacco consumption exceeds 2,250 lbs. per hour.

A further object is to provide a pneumatic conveying system whereby rag tobacco can be conveyed at velocities of about 4,000 c.f.m. over extremely long distances and through an exceptionally high vertical rise and at a rate of 2,500 lbs. per hour and more while, at the same time, not affecting the moisture or temperature of the rag in a harmful manner.

Still another object is to provide a system of this type with an improved discharger for positively assuring complete fill of the associated cigarette-making machine hopper.

A still further object is to provide a system'of the above type which, compared to those proposed in the past, is more simplified, more economical and superior in operation.

An important object is to provide an improved low-cost and simple rag tobacco feeder for a pneumatic system.

A further important object is to provide a pneumatic system of the above type capable of functioning in a single brand, dual brand or multiple brand capacity thereby permitting a choice of brands for each maker and creating flexibility for a row of making machines whereby frequent changes in brands are possible.

Briefly stated, the over-all purpose of the pneumatic system of this invention is to convey cut tobacco from the cut tobacco storage areas to the making machines automatically, as required by the making machines. A sensing device in each making machine hopper operates to detect a low level of tobacco to initiate the prescribed series of events. The system is designed to feed only one of a given number of making machines at a time upon request for out tobacco.

When a request is made by a particular cigarette-making machine, a control unit operates to select the proper making machine and opens the suction side of a separator incorporating the teachings of the present invention, located at the top of the selected making machine hopper. At the same time, the control unit initiates a cycle timing device. Thereafter, a trap door on the tobacco separator is drawn closed and check valves on all of the other separators in the system are closed and drawn into their respective seats by the suction now present in the tobacco feed pipe. Air flow is now established in the system from the cut tobacco to the exhaust of the suction producing device through the selected separator of the making machine requiring tobacco.

When the air flow in the feed pipe or duct reaches the prescribed conveying velocity, a differential pressure switch located in proximity of the feeder senses this condition and causes the feeder to be energized independently and without any connection to the balance of the system other than the feed pipe. Tobacco flow is now established between the storage area and the selected making machine. At the particular separator, the tobacco is separated from the air stream by means of a screen installed between the inlet and discharge end of the separator.

As the air conveyed cut tobacco fills the separator, the pressure drop across the separator progressively increases. When this pressure drop reaches a pre-set level or value, the control unit closes the suction side of the separator. The desired amount of cut tobacco collected on the separator screen is correlated to pressure drop to thereby assure the optimum amount of tobacco to be loaded into the selected cigarette maker hopper, with the cycle timing device operating to serve as a safety factor in preventing overloading of the separator.

The loss of conveying velocity in the feed pipe will now be sensed by the differential pressure switch located near the feeder to thereby cause de-energization of the feeder. The trap door of the separator will now swing open under the influence of gravity and the collected cut tobacco falls into the selected making machine hopper. When this occurs, the low level circuit on the making machine is tie-energized. Provision is made in the control unit to prevent an immediate recall on a maker before the tobacco drops into the hopper in the event there is no other maker with a low level indicated.

The present invention also contemplates a control unit set up either on a random memory network or a sequential demand network. In any event, the master control unit is at rest when no maker is showing a low level.

In addition, controlled air bleeds are incorporated into the feed line of the last maker located on the feed line to prevent an accumulation type build-up which eventually might cause a stop-up in the system. A controlled air bleed in the suction line of the blower is used in systems where multiple feed systems are taken off a single blower. This air bleed is controlled by the motor load to prevent the blower from pulsating on no-load conditions by bleeding air into the system and from overloading on full-load conditions by closing off the air bleed.

In addition to the improved system for conveying cut tobacco from a storage area to a cigarette-making machine, details of the cut tobacco separator associated with each making machine hopper and details of the cut tobacco feeder for supplying tobacco to the system are of a novel and improved nature which will be disclosed in considerable detail in the following.

Other objects and advantages will become apparent from the following detailed description which is to be taken in conjunction with the accompanying drawings illustrating a somewhat preferred embodiment of the invention and in which:

FIG. 1 is a schematic plan view of a system for pneumatically conveying cut tobacco from a storage area to a cigarette-making machine which may constitute one of a number arranged in a row with all either makin one brand of cigarettes or, as shown, arranged and pneumatically connected to manufacture multiple brands with the interconnection of one of the makers, its separator and maker control panel with the master control panel diagrammatically shown;

FiG. 2 is a top plan view of the novel cut tobacco feeder;

FIG. 3 is a longitudinal sectional view thereof taken along the line 33 of FIG. 2;

FIG. 4 is a longitudinal sectional view of the novel tobacco separator associated with the hopper of a cigarette-making machine;

FIG. 5 is a sectional view thereof taken along the line 5--5 of FIG. 4, and

FIG. 6 is a circuit diagram of the electrical network incorporated in the disclosed embodiment of the invention.

General description In the drawings, the pneumatic conveying system for cut tobacco is illustrated and, in accordance with the exemplary embodiment, will comprise a cut tobacco storage area at which is located a feeder 10 and as many other feeders for the same or other brands as is required for feeding the tobacco to the cigarette-making machines 12. A selected number of cigarette making machines 12a to 12g may be manufacturing the same brand of cigarette with perhaps machines 1211 to 12 making another brand for which an identical feeder 10 is employed. A main feed pipe 14 receives the cut tobacco fed by the feeder 10 and by means of the feed stream dividers 16 cooperates in selectively directing the cut tobacco to the demanding maker 12. The operation of each feeder 10 is controlled by means of a pressure differential switch 18 located adjacent its discharge end and in the main stream pipe 14. When the air flow in the main feed pipe 14 reaches conveying velocity following a demand signal from a maker 1.2, the pressure differential switch 18 senses this condition and causes the feeder 10 to be energized independently and without any connection to the balance of the system. The desired air velocity is generated by means of the suction producer or blower 20 coupled with the main suction pipe 22 through the interposed dust removal and collection unit 24 and controlled air bleed 26. The main suction line 22 is coupled with all of the makers I2 in the selected row by means of the dividers 28. Each of the makers is provided with a check valve 30 at its air inlet end and a suction control valve 32 at its air discharge end. Controlle air bleeds 34 are located in the main pipe leading from the feeders at the entrance to the last maker 12 fed thereby to permit air to enter the dividers 16 from two directions, namely, the entrance end of the divider and the straight through exit end. The controlled air leak will, under the circumstances, eliminate the vacuum in the non-conveying section of the main pipe 14, and allows a slight backforce to contact tobacco thrown forward, out of the main airstream, and divert this tobacco direction and return it to the main air stream. A master control panel 36 and the individual maker control panels 38 cooperate in providing the control unit for controlling the operation of the pneumatic system.

Feeder Referring now to the feeder 10, it will be immediately realized that an extremely simple unit construction is contemplated which is adapted to be fed either automatically or manually in any one of a number of ways. Thus, the feeder 10 includes a hopper 40 adapted to receive the rag or cut tobacco. Interiorly of the hopper 40 is a feedup conveyor belt 42 extending over suitably journaled pulleys 4-1- and 46 one of which is suitably connected with the outward shaft of motor 48. The belt 32 is adapted to transfer tobacco onto a metering belt 5% forming part of a metering section which also includes a doffer 52 both of which cooperate in transferring a metered amount of the tobacco into the pick-up transition 54 which is pneumatically coupled with the main pipe 14. The metering belt 54 is likewise mounted on rollers 56 and 58 and together with doifer 52 is driven by motor 60. When the feeder 10 is started by the pressure switch 18, the motor 6t) is energized to operate the metering belt and doffer 52 to thereby feed tobacco into the transition 54. A Sonac sound actuated or photoelectric optically actuated relay 62 is conveniently located behind the doifer 52 such that it is adapted to sense the amount of roll or accumulation of tobacco behind the doifer 52. When this relay indicates the roll is too low, the motor 48 is actuated to operate the feed-up belt 42 to transport the cut tobacco to the metering belt 59. The two motors 43 and may be interlocked electrically so that the feed-up belt 42 can only run when the metering belt 50 is running.

Separator Referring now to the separator 13, the separator 13 is advantageously mounted over the hopper 64 of a cigarette-making machine only fragmentarily shown in the drawing. This machine may assume the form of any one of a number of commercially available cigarette-making machines. Where necessary, the hopper 64 of commercial equipment may require that its capacity be decreased. Be that as it may, the hopper 64 includes Sonac relay sensors 66 or other suitable means for responding to the level of tobacco in the hopper to register the call or request for tobacco from the pneumatic conveying system of this invention. When this occurs, cut tobacco will eventually enter the separator 13 through the check valve 30 and fill the compartment 68 immediately below the separating screen 70 with the air stream passing on through the open suction valve 32. When the compartment 68 is nearly full, the screen 70 is very nearly blocked thereby causing a relatively high differential pressure across the screen. The present invention takes advantage of the development of this pressure drop by employing a differential pressure switch 72 communicating with both the upstream and downstream side of the separator and across the screen 70. Upon the attainment of the desired predetermined pressure drop or pressure differential, the switch 72 is actuated to cause the suction valve 32 to be closed. Subsequently, the trap or discharge door 74 at the base of the separator 13 will open to release the accumulated tobacco into the cigarette-making machine hopper 64.

The check valve 30, in accordance with a successful and somewhat preferred embodiment of the invention, embodies a soft, tough, resilient material contained between a pair of metal discs. The small disc is merely a retainer for holding the larger outside disc. In the closed position, the valve 39 is sucked into the inlet end 76 of the feed pipe and will close and seal over any particles of tobacco that may be found on the valve seat, thereby preventing any back flow air leakage.

The check valve 32 is shifted from a fully open to fully closed position by means of a piston-cylinder 78. This cylinder 78 operates preferably off a four-way solenoid air valve (not shown).

Dust removal and blower systems The dust removal unit 24 is preferably of the self-cleaning tank type with bag filters installed on the suction side of each blower 20 to thereby prevent the dust from passing through the blower units. In this manner, dust and sand erosion of the blower and pallors is substantially eliminated.

The blower or suction units 20 are preferably of the two-stage turbine type developing approximately 60 inches of water pressure on the suction side. It has been found that static pressures of this magnitude are advantageous in handling relatively long conveying runs as are contemplated by the present invention. Runs up to an equivalent of nine hundred feet of straight duct have been handled by the present invention. This particular run included a vertical rise of sixty feet.

The conveying velocity of the system is advantageously adjusted by means of a damper which is preferably installed in the suction line 22. This creates the advantage of having only one velocity adjustment per system and even more important, it permits adjustment of the conveying velocity while the system is in operation.

Master control panel The master control panel 36 is coupled with the makers 12 through the associated maker control panels 38. The essential constituents of the master control panel are schematically illustrated in FIG. 6 and, as shown, evolve about a stepping switch comprising coil 80 and wiper arms 82a, 82b and 820 each of which are adapted to traverse from their respective home positions the associated switch contacts 1-10 corresponding with the number of cigarette-making machines in the particular system under consideration. In this connection, it will be assumed that all ten makers 12a to 12j will be in a common system manufacturing one brand of cigarettes. The system is put in operation and at the start master switch 84 will be closed and the stepping switch arms 82a, 82b and 820 will be in their respective home position as shown with the stepping switch choil 80 de-energized. Assuming for the moment that none of the makers 12a to 121' are calling for out tobacco, all of the tobacco level relays 66 will be de-energized and their respective contacts open and closed as shown. An interrupter in the circuit is in a coil de-energized position with its switch 86 in a closed position.

For purposes of the instant description, it will be assumed that maker 1203 contains a low level of tobacco in its hopper 64d which has been sensed and the level control relay 66d has been energized. When this occurs, the normally closed relay switch tied-2 opens and normally opened relay switch 6603-1 closes whereupon power is removed from contact 4 associated with wiper arm 82a and simultaneously power is applied to the home position of wiper arm 82a through normally closed relay contact 88a. This causes the step coil to be energized. The step coil 80 upon energization, opens the interruptor contact 86 thereby de-energizing the coil 80 to cause the step switch arms 82 to advance to position 1. Since position 1 corresponds to the making machine 12a which presumably is not showing a low level, the step coil 80 is again energized and again breaks its own circuit by opening interrupter contact 86 to thereby advance another step. Thus, the step switch arms 82 will continue to advance step-by-step in a self-interrupted mode of operation until the arms reach a position on the step switch which is not part of a closed circuit. In the present instance, this will be when the arms 82 reach point 4 at which the arms will stop and remain there until the step coil 80 is again reenergized.

As mentioned in the above, all three levels of the step v switch 82a, 82b, and 82c move together inasmuch as they are mechanically coupled. Level 82a controls the actual stepping of the switch as discussed in the above. Level 82b controls the circuits to the solenoid operators 78 associated with the suction valves 32a32j. Level 82c controls the differential pressure switch cycle termination circuits which include the pressure differential switches 72a to 72 In accordance with a commercial application of the invention, the stepping switch operates at approximately 40-60 steps per second in the self-interrupted mode.

When the stepping switch wiper arms 82 left the home position, the normally open or off switch 820! closed to apply power through normally closed relay contact 88d to the overall cycle timer 90. When the stepping switch arms 82 reach position 4, they stop. Consequently, relay 7 8d will .be energized causing the associated suction valve 32d to open. Simultaneously therewith, the pressure differential switch 72d will be placed in the termination circuit through the wiper arm 820 now being associated with contact 4. When either the pressure differential switch 72d or time delay relay contact 90a closes, the latter occurring upon the expiration of the predetermined overall cycle time, relay 88 and time delay relay 92 become energized and held in through respective normally open but closed relay switch 88b and normally closed relay switch 92a which will remain in this position until the expiration of a predetermined period of time determined by the setting of the relay 92. At the same time, relay contacts 88a and 88d which are normally closed will open whereas normally open relay contact 880 closes. When the latter switch closes, the time delay relay 94 becomes energized and, at the same time, the stepping switch coil 80 will be energized through the normally closed relay contact 94a for the duration of the time set for relay 94 thereby forcing the stepping switch arms 82 to advance one step when the relay 94 times out. When this occurs, relay contact 88d opens to reset the time delay relay 90. In addition, when relay 94 times out, its contact 94b closes placing the relay 90 back in the time cycle. Relay contact 88a opens preventing the stepping switch arms 82 from passing through the home position h until relay 92 times out thereby dropping out or de-energizing relay 88. As will be appreciated, contact 88a serves to provide an immediate recall prevention means while the relay contacts 88d and 94b cooperate in resetting the time cycle relay 90.

In actual operation, approximately three seconds are required for the discharger 13 to empty its load and reset the hopper low level sensors 66. This corresponds to the time set on the time delay relay 92. Since the stepping switch arms 82 must pass through the home position h to recall on a maker 12 whose cycle has just been completed and further since this is delayed by the timer 92 and now open relay contact 88a, immediate recall is prevented. The advantages gained by this arrangement are that the delay is not inserted between every call, only those where the unit is going from a higher position to a lower one and that the feeder 10 and conveying system in general are not upset and allowed to come to rest between every stop.

In order to assure complete and reliable resetting of the timer 90, the combination of relay switches 88d and 9411 provide for a period of approximately one-half second for this purpose. Furthermore, timer 90 is intended to be used only for the purpose of a back-up of the differential pressure switch 72. A variance of half-a-second in its timing is easily handled by the system and no problems are encountered. The purpose of the relay contact 82d is to prevent the timer 90 from continuously cycling while the unit is at rest in the home position.

Thus, assuming that no other maker is making a request for tobacco, the hopper arms 82 will continue to advance step-by-step in a self-interrupted mode of operation and will come to rest at the home position. On the other hand, assuming a request is made by either of the machines 12e to Hi or 12a to 12c, the request weights is answered by the wiper arms 82 progressing to the position associated with the requesting machine. The cycle of operation is then repeated.

As will be appreciated, the maker control panels 38 are only required to contain in addition to conventional components, suitable operating lamps or the like and suitable switching to permit change of brands.

Summary When one of the Sonac relays 66 has its generated ultra-sonic beam not broken by rag, a signal identified as a request is forwarded to the master control panel 36 indicating a low hopper level. At the master control panel 36, the request waits if another discharger is calling or progresses onto the stepping switch cycle of operation.

The control system then selects the proper making machine 12 as the stepping switch, takes the request and revolves to the assigned call position. Upon reaching this position, the request signal is changed to a call signal. The call signal then returns to the maker control panel 36 and from there to the compressed air-solenoid actuated suction valve 32 on the discharger 13 over the top of the proper making machine 12. At the same time, the cycle timing device 9% in the control system is started and in somewhat rapid succession, the following events occur: the trap door 74 on the discharger 13 is drawn closed; the check valves 30 on all other dischargers 13 are closed and drawn into their seats by the suction now present in the feed pipes; and air flow is now established in the system from the feeder It to the exhaust of the blower through the discharger 13 of the making machine 12 requiring tobacco.

When the air flow in the feed ducts reaches conveying velocity, differential pressure switch 18 located adjacent the discharge end of the feeder 10 senses this condition and causes the feeder 10 to be energized inde pendently without any connection to the balance of the system other than the feed pipe 14. Tobacco flow is now established between the storage area and the making machine 12. At the discharger, the tobacco is separated from the air stream by means of the screen installed in the discharge between the feed and discharge ends thereof.

As the tobacco fills the discharger 13, the fill area of the separating screen 76 progressively diminishes causing the pressure drop across the screen to increase. When this pressure drop reaches a pre-set level as sensed by the differential pressure switch 72 indicating that the discharger 13 is full or on the expiration of the time set on the cycle timing device 90, the suction valve 32 closes. The loss of conveying velocity in the feed pipe 14 is sensed by the differential pressure switch 18 which de-energizes the feeder 10. The trap door 74 of the discharger 13 now swings open by gravity and the cut tobacco falls by gravity into the making machine hopper 64.

This cycle of operation is repeated for each maker 12 making a request for cut tobacco.

Thus, among others, the several aforenoted objects and advantages are most effectively attained. Although a single somewhat preferred embodiment of the invention has been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.

I claim:

1. An automatic tobacco conveying system for pneumatically conveying tobacco from a storage area to at least one cigarette-making machine, said system comprising: i

a main feed pipe coupled with the source of the stored tobacco and cigarette-making machine;

a tobacco discharged associated with said cigarette-making machine and comprising a housing having an air inlet end coupled with the main feed pipe and an air discharge end, tobacco separating means within the housing for separating tobacco carried by air entering the inlet end, and means for causing the separated tobacco to be discharged into the cigarettemaking machine;

air differential pressure means for forcing air through the pipe at a predetermined conveying velocity;

a tobacco feeder at the source of stored tobacco for feeding the tobacco into the main feed pipe;

and air pressure sensitive means for sensing the air pressure in the main pipe being directly connected electrically to the feeder and being electrically independent of other electrical circuitry of the system and said air pressure sensitive means actuating the operation of the feeder upon attainment of the predetermined conveying velocity of the air to the cigarette-making machine, said air pressure sensitive means being the sole actuating means for the feeder, the air pressure sensitive means being a differential pressure switch, said feeder having a drive means for driving the feeder and metering the tobacco into the main feed pipe and electrical coupling means for electrically coupling the switch directly with the drive means electrically independent of other electrical circuitry of the system.

2. The invention in accordance With claim 1 wherein the feeder comprises a discharge end, a hopper end and a. belt conveyor having a discharge end for transferring tobacco to a metering station, said drive means including a metering conveyor at the metering station for receiving the tobacco discharged by the belt conveyor to the feeder discharge end into the main pipe, and level sensing means for sensing the level of tobacco on the metering conveyor and when the level exceeds a predetermined limit temporarily changing the operation of the belt conveyor and the discharge of tobacco on the metering belt by a corresponding amount.

3. The invention in accordance with claim 2 wherein a dotfer isdriven in synchronization with the metering conveyor.

4. An automatic tobacco conveying system for pneumatically conveying tobacco comprising a tobacco discharger comprising a housing having an air inlet including a conduit and an air discharge end including a conduit, a tobacco separating screen arranged within the housing intermediate the inlet and discharge ends for separating tobacco carried by air entering the inlet end; a differential pressure switch connected across the screen for sensing the air pressure thereacross; means for causing the separated tobacco to be discharged into the hopper of a cigarette-making machine upon the sensing of a predetermined pressure drop across the screen by the switch, said means comprising a suction valve at the discharge end for permitting air to pass through the housing when open and to prevent air to pass therethrough when closed to facilitate discharge of the separated tobacco from the housing into the hopper of the making machine; a valve actuating means being coupled with the suction valve for shifting the valve between an open and closed position; circuitry coupling the switch and the valve actuating means; and a check valve being at the air inlet end to isolate the dis-charger from another discharger of said system having tobacco conveyed thereto.

5. The invention in accordance with claim 4 wherein the housing includes a pivotal trap door pivotal from a normally open position at which the interior of the housing communicates with the hopper of the making machine to a closed position when the suction valve opens to permit tobacco to be conveyed to the discharger and separated on the screen and thereafter opened when the suction valve is closed to cooperate in discharging the separated tobacco into the associated hopper of the making machine.

6. The invention in accordance with claim 5 wherein the hopper of a cigarette-making machine is connected with the discharger, a tobacco level sensing device is coupled with the hopper and the sensing device is adapted to detect a low level of tobacco in the hopper and initiate the pneumatic conveyance of tobacco to the discharger.

7. The invention in accordance with claim 6 wherein a main feed pipe couples the inlet end of the housing with a source of the stored tobacco, a tobacco feeder at the source of stored tobacco for feeding the tobacco into the main feed pipe.

8. The invention in accordance with claim 7 wherein air pressure sensitive means are included for sensing the air pressure in the main pipe and actuating the operation of the feeder upon attainment of a predetermined conveying velocity of the air to the discharger through the main pipe.

9. The invention in accordance with claim 8 wherein a main suction pipe couples the air discharge end of the discharger with a source of suction, a blower at the source of suction and a filter in the suction pipe interposed between the blower and the discharger.

10. The invention in accordance with claim 9 wherein a plurality of the dischargers associateed with cigarettemaking machines are in said system and all being similarly connected with the main feed pipe and the main suction pipe and a controlled air bleed is in the main feed pipe between the last discharger the furthest distance from the feeder and the next to last discharger for preventing build-up of tobacco and eventual stop-up of the system.

11. The invention in accordance with claim 10 wherein at least one more feeder with another of the main feed pipes is coupled with at least one of the dischargers in place of the first defined feeder and main feed pipe for feeding different tobacco for the manufacture of a different brand of cigarette.

12. The invention in accordance with claim 11 wherein an adjustable controlled air bleed means is disposed in the main suction pipe adjacent the blower to prevent the blower from pulsating on no-load conditions and from overloading on full-load conditions.

13. The invention in accordance with claim 12 wherein an electrical network including the discharger pressure differential switch, the hopper level sensing device .and the suction valve solenoid in circuit receives requests for tobacco made by the making machine in the order made.

14. An automatic tobacco conveying system for pneumatically conveying tobacco from a storage area to a plurality of cigarette-making machines, said system comprising a tobacco discharger associated with each making machine having means for separating the tobacco from an air stream passing therethrough, a main feed pipe coupled with the source of the stored tobacco and each of the dischargers, air differential pressure means for forcing air through the main feed pipe to the dischargers, a tobacco feeder at the source of stored tobacco for feeding the tobacco into the main feed pipe, and a controlled air bleed in the main feed pipe between the last discharger the furthest distance from the feeder and the next to last discharger for preventing build-up of tobacco and eventual stop-up of the system.

15. An automatic tobacco conveying system for pneumatically conveying tobacco from a storage area to a plurality of cigarette-making machines, said system comprising a tobacco discharger associated with each making machine having means for separating the tobacco from an air stream passing therethrough, said tobacco discharger comprising a housing having an air inlet end including a conduit coupled with the main feed pipe and an air discharge end including a conduit, tobacco separating means within the housing for separating tobacco caried by air entering the inlet end, and means for causing the separated tobacco to be discharged into the cigarette-making machine, said means comprising suction valve at the discharge end for permitting air to pass through the housing when open and to prevent air to pass therethrough when closed to facilitate discharge of the separated tobacco from the housing into the hopper of the making machine, a check valve being at the air inlet end to isolate the discharger from another discharger of said system having tobacco conveyed thereto, a main feed pipe coupled with the source of the stored tobacco and a plurality of the dischargers leaving remaining at least one discharger uncoupled with said main feed pipe, air differential pressure means for forcing air through the main feed pipe to the dischargers, a tobacco feeder at the source of stores tobacco for feeding the tobacco into the main feed pipe, at least one more feeder with another of said main feed pipes being coupled through its associated main feed pipe with said at least one of the remaining dischargers and coupled with said air pressure means for feeding different tobacco for the manufacture of a different brand of cigarette.

16. The invention in accordance with claim 15 wherein divider means in the main feed pipes extend to the associated dischargers and quick disconnect means at between the divider means =and associated dischargers for facilitating the disconnection of a discharger from one main feed pipe for connection to another main feed plpe.

17. The invention in accordance with claim 15 wherein the air differential pressure means includes a main suction pipe coupled with each discharger, a blower connected with the suction pipe and an adjustable controlled air bleed means disposed in the suction pipe adjacent the blower to prevent the blower from pulsating on no-load conditions and from overloading on full-load conditions.

References Cited UNITED STATES PATENTS 1,937,158 11/1933 Lorentz 30259 2,140,128 12/1938 Craggs 302 2s 2,826,459 3/1958 Octiker 3O235 2,972,500 2/1961 Esenwein 302-28 3,077,365 2/1963 Fischer 30228 3,106,427 10/ 1963 Mortimer 302-28 ANDRES H. NIELSEN, Primary Examiner. 

